The Los Angeles Lakers’ four-game winning streak could be in serious jeopardy on Martin Luther King Jr. Day. The team announced on Sunday that an MRI on Lonzo Ball’s left knee revealed a minor sprain, and have listed him as questionable for Monday’s game against the Memphis Grizzlies.

Update: Lonzo Ball, who injured his knee in yesterday’s game against the Dallas Mavericks, had an MRI today. Results of the MRI revealed a minor left knee sprain.

Ball initially suffered the setback during L.A.’s overtime win against the Dallas Mavericks on Saturday. The rookie out of UCLA played 43 minutes in that game, tallying nine points, seven rebounds and seven assists.

Zo awoke to soreness on his left knee on Sunday morning, and underwent the MRI in Memphis shortly thereafter.